Abstract
Cartilaginous metaplasia is a rare but well-documented phenomenon occurring in the wall of odontogenic keratocyst. The mural cartilage not associated with odontogenic keratocyst has been reported only once in a maxillary teratoid cyst of congenital origin to our knowledge. A case presented is a 38-year-old man with intraosseous keratinizing epidermoid cyst in the mandible, the wall of which contained a nodule of mature hyaline cartilage. The present lesion likely represents a previously undescribed, histologic hybrid consisting of orthokeratinized odontogenic cyst and cartilaginous heterotopia.